Growth, Characterization, and Properties of Epitaxial Metal/Nitride Superlattices

外延金属/氮化物超晶格的生长、表征和性能

• 批准号: 9423873
• 负责人: Scott Barnett
• 金额: $ 31.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-15 至 1999-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9423873&HistoricalAwards=false
• 关键词: Growth; Characterization; Properties; Epitaxial; Metal

The aim of this research is to investigate strengthening mechanisms in deposited epitaxial single-crystal nitride/metal superlattices where the layers have different slip systems. Materials systems are NbN/Mo, NbN/W, VN/Cr, AlN/Mo, and AlN/W, providing both cubic-B1/cubic-BCC and hexagonal-wurtzite/cubic-BCC combinations. Both (001) and (111) oriented MgO and W substrates are used. It will be determined if AlN can be grown in a cubic structure when surrounded with cubic (001) layers. These materials should exhibit large strength and hardness enhancements due to the superlattice structure. Correlations between layer characteristics, strength, and hardness will provide new information on strengthening mechanisms. Changes in the layer lattice mismatch (in superlattices containing alloy VN-NbN or Cr-Mo layers) are used to produce superlattices with both coherent and incoherent interfaces. Unlike previously-studied nitride/nitride superlattices, these layers are immiscible such that the structures are stable and retain their desirable characteristics at high temperatures. Structure a nd property studies versus annealing time and temperature are carried out, and the results compared with results from nitride/nitride superlattices. %%% There is technological interest in nitride/nitride superlattices where early results show dramatic improvements over conventional nitride coatings in cutting tools.

本研究的目的是研究沉积外延单晶氮化物/金属超晶格的强化机制，其中各层具有不同的滑移系统。 材料系统包括 NbN/Mo、NbN/W、VN/Cr、AlN/Mo 和 AlN/W，提供立方 B1/立方 BCC 和六方纤锌矿/立方 BCC 组合。使用 (001) 和 (111) 取向的 MgO 和 W 基板。 将确定当 AlN 被立方 (001) 层包围时是否可以以立方结构生长。由于超晶格结构，这些材料应表现出较大的强度和硬度增强。层特性、强度和硬度之间的相关性将为强化机制提供新的信息。 层晶格失配的变化（在含有合金 VN-NbN 或 Cr-Mo 层的超晶格中）用于产生具有相干和非相干界面的超晶格。 与之前研究的氮化物/氮化物超晶格不同，这些层是不混溶的，因此结构稳定并在高温下保持其所需的特性。进行了结构和性能随退火时间和温度的研究，并将结果与​​氮化物/氮化物超晶格的结果进行了比较。 %%% 人们对氮化物/氮化物超晶格产生了技术兴趣，早期结果显示切削工具中的传统氮化物涂层相比有了显着改进。